Sand-blast machine



March 6, ,1 928.

G. c; FATSCHER ET AL SAND BLAST MACHINE Filed March 26 1923 3 Sheets-Sheet 1 O 1 0 o o BY JM A TTORNE Y6 March 6, 1928.

-G. C. FATSCHER ET AL SAND BLAST MACHINE File d March 26 1923 3 Sheets-Sheet 2 IN VEN TOR 6; sakes 0. F34 Tsch'fi ATTORNEYLX March 6, 1928.

G. C. FATSCHER ET AL SAND BLAST MACHINE Filed March 26, 1923 3 Sheets-Sheet INVENTOR Gsones c. FflTSc'l/ER CLflRE CE 5, BILL/N65 ATTORNEYS.

Patented Mar. 6, 1928 UNITED STATES PATENT OFFICE.

GEORGE C. FATSCHER AND CLARENCE E. BILLINGS, OF NEW HAVEN, GONNEGIICUT,

ASSIGNORS TO THE NEW HAVEN SAND-BLAST COMPANY, OF NEW HAVEN, (JON- NECTICUT, A. CORPORATION OF CONN EC'IEICU'CE.v

SAND-BLAST MACHINE.

Application filed March 26, 1923. Serial No. 627,679.

Our invention relates to sand blast machines, and particularly to machines 0-1: the

self-contained type, in which the sand or like abrasive material isautomatically recovered and returned to the blast mechanism during the operation of the barrel.

Among the objects of our invention'may be mentioned- (1) Improved ventilation of the barrel in order to maintain the blast sand clean and in condition for its most efiicient use;

(2) Greater facility in loading and discharging the barrel;

(3) Improved means for effecting the recovery and re-use of the sand;

(4) A construction and assembly of the constituent elements of the machine which facilitates assembly, repair and replacement of parts; 7

Other features of improvement hereinafter described or shown in the accompanying drawings in which Fig. l is a front end elevation of a ma chine which embodies our invention in one form; r

Fig. 2 is a vertical section on the line 22, Fig. 1;

Fig. 3 is a vertical section through one of the blast nozzles;

Fig. 4: is a horizontal section through the blast end of the machine; and

F ig. 5 is a broken end elevation of the same.

The present apparatus possesses various structural and operatin advantages over its prototypes illustrate in the patent-to Dreisbach No. 948,271, February 1, 1910, and the copending application of C. E. Billings filed herewith.

The barrel proper comprises a frusto-conical rotary body 6 of relatively heavy weight sheet metal, for the reception of the castings which it isdesired to clean by the sand blast. As here shown, the body 6 is provided on its inner face with tumbling cleats 6 and is perforated to form a screen, for the purpose hereinafter explained. It is clamped between the rotary heads 7 and 8 at opposite ends thereof by longitudinally extending tie bolts 9 exterior to the screen body. Flanges or lugs 10 and 11 on the respective heads, position and center the screen with repectthereto. The exposed nuts 12 at the charging end of the barrel permit their ready attachment and detachment for assembling and disassembling the barrel structure. i

Surrounding and spaced from the screen is w automatically convey to one end of the barrel the sand which falls through the screen after playing upon the castings. The spiral 15 is apertured or slotted at predetermined points to accommodate the tie bolts'9 which pass therethrough. As shown in the drawings, the rib 15 reaches from the shell 13 to the screenG. As a matter of practical construction it is preferred to leave a slight clearance between the rib and screen, since assembly of the parts is thus facilitated. 1

in either case, however, the rib is secured in position by screws pasing through the shell ,13 and taking into lugs or flanges 15 offset from the outer margin of the rib.

At the chargingand discharging end of the barrel, a closure diaphragm 16 is provided. In order to permit ready access to the interior of the barrel, this diaphragm'is made independent of the head 7 and com prises a semicircular closure area, integral with a ring 17 by which it is secured, as by cap screws 18, to the head .7. A cooperating semi-circular door 19 is hinged atr20 to the of the barrel.

Botlidiaphragm anddoor on their in nor faces are provided with renewable liniiig plates 24 spaced away by studstapped is pierced by ventilation holes 26, to p rmit a draft through the blast chamber to carry off dust. The spacing of the lining plate from the door-permits the escape of the draft around the free margins of the plate while at the same time preventing diaphragm 16 and completes the removable The door 1 to receive the securing screws 25. The door entering the aperture 29.

send, through the head to the elevator scoops 33.

operation;

' zles 30, but

the blast sand from being ejected through the holes 26. Atthe'opposite end of the chamber, the. head 8 is integral with the closure diaphragm 27wliich is also preferably perforated at 28 for ventilation purposes. 1t is centrally apertured at 29 to accommodatethe blast, nozzles 30. A guard 31 of any suitable sort, which may be detachablyisecuredin anyway to the nozzles, prevents the castings from At appropriate points, preferably. .ar ranged radially outside the points ofuattachment of the tie bolts 9, the head 8 has openings 32 formed therein to permit the returned by the spiral riblfi, to pass The latter are carried by 'or.- are integral with the head 8, and are. here shown as webs extending between the latter and the spacedflange 3-i-which with the head, con- "shaft 45 carrying fast and loose pulleys 46-4? respectively. a

Brackets 48 boltcdto the base frame carry a stationary. selniecircular closure plate 49, and in turn support a second set of brackets 50 carrying a complementary semi-circular closure plate 51 which, with itsassociated parts, completes the closure of. the outer end of the elevator drum. Into this closed drum opens the suction pipe 52 leading to a draft fan (not shown) which creates a' suction through the barrel: sufiicient not only to carry off the air introduced by the blast nozalso .to create. a draft through the barrel'which removes dust.

I Mounted on the bracket 50 is the hopp r 53 to which the recuperated sand is delivered by the elevator buckets, and'from which the y sand is admitted through slide valves 54; to

the blast1nozz1es30 supported beneath the hopper. .Diiferent angular inclinations are imparted to the nozzles to cover different portions of the charge within the screen.

The nozzle construction is indicated in Fig. 3. The sand descends frointhe hopper through a throat 55 into a mixing chamber 56,to which opens onone side the air pipe 57 aligned with the nozzle 30of greater internal diameter on the other side. The nozzle is preferably detachably held in place by a screw bushing 58-passed over the nozzle and holdin its head 59 to a conical seat in the wall of the mixing chamber. The

in Figs. 1 and 2, the latches latter is preferably of spherical internal con- .tour and of sulficient size to accommodate a quantity of sand in excess of that delivered through the nozzle. The excess sandforms a lining for the chamber which prevents 1nurious scouring of the walls by the sand under the influence of the blast, as well as affording a sand reserve which insures a steady blast action regardless of temporary variations in the feed from the hopper 53.

'lhe operation of the apparatus is as follows: When the barrel is to be charged, it is preferably brought to the position shown Al released and the door 19 swung down. The castings or the like are then chargedinto the screen (3 through the door opening, and the door swung up and secured inclosed position. The driving belt is now shifted to the fast pulley l6 and the barrel thus set in motion. The suction mittcd to the nozzles, and the sand valves of opened, so that the sand blast days upon the castings as they are tumbled in the rotating drum.

.As the sand charge it escapes through the holes in the screen (i and enters the annular chamber 14- betwecn the screen and the shell 13. The

direction of rotation of the barrel is such that the spiral rib l5 forces this spent sand toward the head 8 through which it escapes, by ports 32, to the elevator buckets 33. By these it is lifted and returned to the hopper 53, from which it feeds again t'o'the blast nozzles.

The exhaust fan exerting suction through the dra ft pipe 52 carries oil the dust which results from the blast operation and thus not onl kee s thesand clean but revents y P P contamination of the surrounding air.

.When the castingshave been sufiiciently treated, the blast is cut off and the barrel halted-preferably with the dOOr 19in the up position illustrated. It may then be unlatched, swung down, secured open by the latch 23, and the barrel rotated. As the door opening moves downward, the castings fall out and may be received 1n a wheelbarrow or other receptacle for removal. The

inclination of the barrel wall towardthe door renders the automatic discharge of the barrelpractic'ally complete. Inany event it' facilitates the removal of any castings which may remain within, and if rotation is continued, complete evacuation of the charge may be thus obtained.

Access to the interior of the barrel is readily efi'ected without ,dismounting, by removal of the closure diaphragm l6 and door 19 by the barrel body 6, it is merely necessary to remove the nuts 12 from the tie bolts 9 and the cap screws which hold the shell 13 to the head 7, whereupon the latter may be relilters down through the,

fan is started, the blast is ad- 12o unscrewing the cap screws18. To replace" 7 moved and the new barrel body placed in position. The plates 24 at the front of the barrel, which are perhaps the most subject to wear, may be replaced without any disassembly, since the door opening is sufiicient ly large to admit a workman to the entrance of the barrel for replacement of the blast nozzles when this is necessary. The same is true with respect to the nozzles, since the door opening is of sufficient size to permit a workman to enter the barrel, or to reach lnto the barrel, remove the guard 31, and detach the nozzle securing bushings 58.

Various modifications in details of con-' struction and arrangement of partswill readily occur to those skilled in the art,

which do not depart from what we claim as our invention.

o claim- 1. In a rotary sand blast barrel, a frustoconical barrel body, heads at opposite ends of the body, and a charging and discharg ing door opening at the end of greater diameter, in combination with sand blast means at the opposite end of the body.

2. A rotary blast barrel comprising a rotary shell, a frusto-conical perforated body arranged within and rotating with the shell, a closure member for the body and shell elements at the end of greater diameter of the frusto-conical body, said end closure comprising a SQll'll-CllCUlfll member rigid with the frusto-conical body member, a second semicircular door complementary to said fixed member and completing the closure, hinge means for supporting the pivoted portion of the closure upon the fixed portion thereof, latching meansforholdingsaid pivoted portion in closure position, and supplementary latching means for holding said pivoted portion in fully open position.

.3. In a rotary sand blast apparatus, a perforated body for containing a charge, a surrounding shall spaced therefrom, rotary heads between which said body and shell extend, a spiral conveyor arranged in the interspace between the body and shell, and tie bolts passing through said spiral and engaging said heads to clamp the body and shell therebetween.

- et. In a rotary sand blast apparatus, a perforated body member, a shell surrounding but spaced therefrom, heads at opposite ends of said body and tie bolts extending between said heads and arranged in the lnterspace between the body and shell, a spiral rib arranged in said interspace for conveying to one end of the. barrel the sand passing through the perforated body, the head at the end to which said spiral delivers being apertured at a point located radially outside the point of attachment of the bolt.

In a rotary sand blast barrel, a frustoconical perforated barrel body, a cylindrical shell surrounding but spaced therefrom, r0 tary heads at opposite ends of and common to said frusto-conical barrel body and shell, the ends of which bear againstthe opposed faces of said heads, together with tie bolts extending between said heads and located between the shell and frusto conical body and serving to unite the said parts into a rigid barrel unit.

In testimony whereof we have signed our names to this specification.

GEORGE o. FATSOHER. CLARENCE E. BILLINGS. 

